Automatic detection of bruises in fruit using Biospeckle techniques

Abstract

This paper present a automatic analysis spatial-temporal speckle correlation technique applied for the bruises detection of different Colombian fruits namely apple and pear for the first time. The method is non-invasive, non-destructive and noncontact and is based on the study of variations in Biospeckle activities in short time data acquisition. The mount consist the 10mw LASER He-Ne 633nm as coherent light source, a diffuser, a USB camera, a control circuit of movement and stepper motor. Physical phenomena present absorption, scattering and interference. Temporal and spatial changes of subjective speckle pattern of the fruit have been measured in thirty samples each two seconds for a total analysis time of one minute. Using the above technique the cross-correlation coefficients of speckle pattern have been calculated. The cross-correlation coefficient change subject to the bruising in section fruit. Significant changes of cross-correlation coefficient values were observed in struck sections of fruit regard to sections not struck from the same. This work concluded that variance the cross-correlation coefficient is higher in struck sections of fruit regard to sections not struck from the same, that rapid analysis of samples in short time data acquisition can be used for quality control in fruit, impact detection not appreciated by visual inspection and others.